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X1.0 solar flare on 1981-04-20
ClassX1.0NOAA report
Peak16:141981-04-20 UTC
Duration98 min
Peak flux1.0e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 395 / 491 |
| Rank in year | 33 / 4022 |
| Other M/X flares that day | 2 |
| M/X flares that month | 87 |
| Solar cycle | Cycle 21 |
| Position on disk | N12W77 |
| Active region | AR 3035 (35 flares) |
Compared with the strongest flares of 1981
X5.9
X5.5
X4.0
X3.6
X3.5
X3.1
X3.0
X2.7
X2.6
X2.5
X2.4
X2.3
Other M/X flares that day
All times UTC. Until June 2017 classes are NOAA's reports of the time (GOES-15 and earlier included a 0.7 scaling factor); later classes come from calibrated GOES-16/18 data, so the same flare reads about 1.4× larger. Do not compare the two periods directly.
← X1.3 1981-04-18X1.4 1981-04-24 →
About this page
A X1.0 flare that began 1981-04-20 16:12 UTC; No. 33 of 4,022 C-class-or-larger flares in 1981.